Big in Japan: The importance of riparian corridors for Orthoptera

Abstract

There are few studies on the Orthoptera of the floodplains, paddy fields, and levee embankments of Japan's riparian corridors. The research which has been undertaken indicates a relatively rich fauna (33% of Japan's grasshopper species recorded) with endangered species (e.g. Eusphingonotus japonicus) found on gravel floodplains, although diversity is restricted by forest cover and unfavorable land uses (e.g. agriculture). Management should focus on the alteration of levee mowing regimes to benefit orthopterans, and the control of invasive plant species and successional processes along river corridors, which appears to be important for grasshoppers of gravel substrates. Integrated Green Grey Infrastructure (IGGI) measures (levee terraces of Asteraceae plants) may enhance populations of Orthoptera and conserve declining plants such as Aster tripolium in Tokyo. More research is required throughout Japan to accurately determine the orthopteran fauna and appropriate conservation measures, particularly along super levees and in paddy fields.